Ultra-High Performance Supercritical Fluid Chromatography Applications for Natural Products Analysis

Ultra-high performance supercritical fluid chromatography (UHPSFC) is a separation technique that provides an increase in selectivity, efficiency and sensitivity. UHPSFC uses compressed CO2 as the primary mobile phase to leverage the chromatographic principles and selectivity of normal phase chromatography while providing the ease of use and method development simplicity of normal-phase LC. The use of CO2 as primary solvent results in significant savings in solvent costs and solvent waste disposal. The miscibility of CO2 with a wide range of polar and non-polar organic solvents has made the liquid CO2 based mobile phase versatile enough to separate a much wider variety of natural product compounds. UHPSFC in combination with sub-2 µm particles and either diode array ultraviolet, evaporative light scattering, or mass spectrometric detection has been shown to be a valuable technique for the analysis of natural products. In this study, sub-2 µm particle CO2 based UHPSFC was investigated for the separation and analysis of different natural products including terpene lactones and ginkgolic acids in Ginkgo biloba, cannabinoids in cannabis and cannabis products, volatiles in traditional medicine, beta-carotene, lipids and other compounds in different extracts. The method development and optimization involved the investigation of different columns, modifiers and instrument conditions. The benefit of UHPSFC will be highlighted and discussed compared to the traditional gas chromatography and normal phase chromatography for natural product analysis. For most of the applications better separation and selectivity was obtained with significant reduction in analysis time compared to alternative techniques such as GC which requires derivatization.